1. Field of the Invention
The present invention relates to a touch sensing apparatus and method thereof that can accurately judge a touch through an increase in a magnitude of capacitance variations at the time of a touch.
2. Description of the Related Art
A touch sensing apparatus such as a touch screen, a touch pad, or the like, an input apparatus attached to a display apparatus to provide an intuitive input method to a user, has recently been widely used in various electronic devices such as portable phones, personal digital assistants (PDAs), navigation apparatuses, and the like. In particular, recently, with an increase in demand for smart phones, the rate at which touch screens have been adopted as touch sensing apparatus capable of providing various input methods in a limited form factor has increased on a day by day basis.
Touch screens used in portable devices may be divided into resistive type touch screens and capacitive type touch screens, according to a method of sensing a touch. The capacitive type touch screen has advantages in that it has a relatively long lifespan and various input methods and gestures may be easily implemented therein, such that use thereof has markedly increased. Particularly, a multi-touch interface may be more easily implemented using the capacitive type touch screen, as compared to the resistive type touch screen, such that it is widely used in devices such as smart phones, and the like.
The capacitive type touch screen judges whether or not a touch is made by sensing a variation in capacitance generated by a touch. As a variation in a magnitude of capacitance increases, the touch may be more accurately judged. In order to increase the magnitude of capacitance variations, a high voltage driver may be used. However, in this case, a high voltage process and an additional circuit charge pump for forming a high voltage driving signal are required, such that complexity of a circuit increases. Therefore, it may not be easy to implement the capacitive type touch screen, and implementing the capacitive type touch screen in an economical manner may be problematic.